We propose to continue our studies of the use of metallic surfaces and particles for applications in fluorescence based DMA analysis. During the initial funding period of this project we demonstrated that dye- labeled DMAs in the proximity of hetrogeneous silver particles display increased quantum yields, increased Forster resonance energy transfer (FRET) distances and increased photostability. We also showed that fluorophores immobilized near continuous metal surfaces can induce highly efficient directional emission into a substrate, a phenomenon we call surface plasmon-coupled emission (SPCE). In the next period we will extend these studies to use precisely nanofabricated metallic structures designed for use with specific fluorophores and applications. The desired effects will be obtained by coupling of the ground and/or excited fluorophores with surface plasmons in the metal structures. We propose the following specific aims: Specific Aim 1: Development of regular arrays of defined shape particles for optimized MEF to increase the detection sensitivity of dye-labeled nucleic acids bound to surfaces. A. Fabricate metal particles arrays with various sizes, shapes, and spacing, with the goal of maximum sensitivity from different wavelength fluorophores. B. Perform single molecule spectroscopy to determine the photostability of fluorophores near the metallic particles. Specific Aim 2: Development of semi-continuous periodic metallic surfaces for PCF of fluorophore-labeled DNA bound to surfaces. A. Fabricate nanohole arrays, nanorings, and gratings for optimal fluorophore-plasmon coupling. B. Develop wavelength-selective plasmonic structures for directional emission for DNA analysis. Specific Aim 3: Applications of the metallic structures described in Specific Aims 1 to 2 to enhance current DNA array platforms. A. Develop DNA hybridization protocols on the metallic nanostructures. B. Apply the nanostructures array for identification of class B biohazard agents. C and D. Apply the nanostructures for analysis of the cystic fibrosis transmembrane regulator gene (CFTR).